[FFmpeg-user] How to duplicate 1st line

[Ulf Zibis]

Hi again,

Am 06.01.19 um 14:27 schrieb Ulf Zibis:
> because of a noise in the 1st line of my video, I want to duplicate the
> 2nd line to the first. I tried this and got an error about invalid
> horizontal crop value:
> ffmpeg -i in.vob -vf
> "split[in1][in2];[in1]crop=in_w:1:0:1[top];[in2]crop=in_w:in_h-1:0:1[main];[top][main]
> vstack"out_fill-top_.mp4
Thanks to a hint from Moritz this works with up- and downsampling the
colour resolution:

ffmpeg -i in.vob -vf "format=yuv422p,split[in1][in2];[in1]crop=in_w:1:0:1[top];[in2]crop=in_w:in_h-1:0:1[main];[top][main]vstack,format=yuv420p"out_fill-top_.mp4

-Ulf